17-12 Lewis Acids and Bases

1. Can CH₃NH₂ be a lewis acid or a lewis base?

2. Trimethylamine (CH₃)₃N can react with diborane B₂H₆ after its dissociation to form (CH₃)₃N-BH₃. Which one is the lewis acid? Which one is the lewis base?

3. In the reaction

which one is the lewis base?

4. In the reaction

Which one is the lewis acid? and the lewis base?